/*
 *
 *  Copyright (C) 2008-2023, OFFIS e.V.
 *  All rights reserved.  See COPYRIGHT file for details.
 *
 *  This software and supporting documentation were developed by
 *
 *    OFFIS e.V.
 *    R&D Division Health
 *    Escherweg 2
 *    D-26121 Oldenburg, Germany
 *
 *
 *  Module:  dcmnet
 *
 *  Author:  Michael Onken
 *
 *  Purpose: Base class for Service Class Users (SCUs)
 *
 */

#ifndef SCU_H
#define SCU_H

#include "dcmtk/config/osconfig.h" /* make sure OS specific configuration is included first */

#include "dcmtk/dcmdata/dctk.h"    /* covers most common dcmdata classes */
#include "dcmtk/dcmnet/dcasccff.h" /* for reading a association config file */
#include "dcmtk/dcmnet/dcasccfg.h" /* for holding association config file infos */
#include "dcmtk/dcmnet/dcompat.h"
#include "dcmtk/dcmnet/dimse.h"    /* DIMSE network layer */
#include "dcmtk/ofstd/oflist.h"

// include this file in doxygen documentation

/** @file scu.h
 *  @brief general Service Class User (SCU) class
 */

/** Different types of closing an association
 */
enum DcmCloseAssociationType
{
    /// Release the current association
    DCMSCU_RELEASE_ASSOCIATION,
    /// Abort the current association
    DCMSCU_ABORT_ASSOCIATION,
    /// Peer requested release (Aborting)
    DCMSCU_PEER_REQUESTED_RELEASE,
    /// Peer aborted the association
    DCMSCU_PEER_ABORTED_ASSOCIATION
};

/** Storage mode used for DICOM objects received via C-STORE
 */
enum DcmStorageMode
{
    /// Ignore any objects received via C-STORE
    DCMSCU_STORAGE_IGNORE,
    /// Try to store the objects to disk
    DCMSCU_STORAGE_DISK,
    /// Try to store to disk in bit-preserving mode. This is especially useful
    /// for huge files that cannot fully be received in memory since the data
    /// is directly streamed to disk. Originally, this was introduced for DICOM
    /// signatures which can be kept valid this way.
    DCMSCU_STORAGE_BIT_PRESERVING
};

/** Base class for C-FIND, C-MOVE and C-GET responses
 */
class DCMTK_DCMNET_EXPORT QRResponse
{
public:
    /** Standard constructor.
     */
    QRResponse()
        : m_messageIDRespondedTo(0)
        , m_affectedSOPClassUID()
        , m_dataset(NULL)
        , m_status(0)
        , m_statusDetail(NULL)
    {
    }

    /** Destructor, cleans up internal memory (dataset if present).
     */
    virtual ~QRResponse()
    {
        delete m_dataset;
        delete m_statusDetail;
    }

    /// The message ID responded to (mandatory response field,
    /// equals message ID from request)
    Uint16 m_messageIDRespondedTo;

    /// Optional response field according to part 7 of the standard.
    /// If present, equals SOP Class UID from request.
    OFString m_affectedSOPClassUID;

    /// Conditional response field (NULL if absent). From the standard (2009,
    /// part 4, C.4.2.1.4.2), for C-MOVE: In Q/R if no C-STORE sub-operation
    /// failed, Failed SOP Instance UID List (0008,0058) is absent and
    /// therefore no Data Set shall be sent in the C-MOVE response. Further
    /// rules: Statuses of Canceled, Failure, Refused, or Warning shall
    /// contain the Failed SOP Instance UID List Attribute; status of
    /// Pending shall not.
    DcmDataset* m_dataset;

    /// The returned DIMSE status (mandatory Response Field)
    Uint16 m_status;

    /// Status detail (NULL if absent). For some DIMSE return status codes,
    /// an additional dataset is sent which gives further information (i.e.
    /// in case of warnings or errors).
    DcmDataset* m_statusDetail;

private:
    /** Private undefined copy constructor.
     * @param other The find response to copy from
     */
    QRResponse(const QRResponse& other);

    /** Private undefined assignment operator.
     *  @param other The find response that should be assigned from
     *  @return Reference to this
     */
    QRResponse& operator=(const QRResponse& other);
};

/// Base class representing for single C-GET or C-MOVE response
class DCMTK_DCMNET_EXPORT RetrieveResponse : public QRResponse
{
public:
    /** Standard constructor
     */
    RetrieveResponse()
        : m_numberOfRemainingSubops(0)
        , m_numberOfCompletedSubops(0)
        , m_numberOfFailedSubops(0)
        , m_numberOfWarningSubops(0)
    {
    }

    /** Destructor, cleans up internal memory
     */
    virtual ~RetrieveResponse()
    {
    }

    /** Prints response to INFO log level.
     */
    void print();

    /// Number of remaining sub operations (in Q/R: C-STORE calls).
    /// For Q/R MOVE and GET, for status of pending this field shall be filled.
    /// For others, the field may be filled.
    Uint16 m_numberOfRemainingSubops;

    /// Number of successfully completed sub operations (in Q/R: C-STORE calls).
    /// For Q/R MOVE and GET, for status of pending this field shall be filled.
    /// For others, the field may be filled.
    Uint16 m_numberOfCompletedSubops;

    /// Number of failed sub operations (in Q/R: C-STORE calls).
    /// For Q/R MOVE and GET, for status of pending this field shall be filled.
    /// For others, the field may be filled.
    Uint16 m_numberOfFailedSubops;

    /// Number generated warnings generated by sub operations (in Q/R: C-STORE calls).
    /// For Q/R MOVE and GET, for status of pending this field shall be filled.
    /// For others, the field may be filled.
    Uint16 m_numberOfWarningSubops;

private:
    /** Private undefined copy constructor
     *  @param other Response to copy from
     */
    RetrieveResponse(const RetrieveResponse& other);

    /** Private undefined assignment operator
     *  @param other Response that should be assigned from
     *  @return Reference to this
     */
    RetrieveResponse& operator=(const RetrieveResponse& other);
};

/** Base class for implementing DICOM Service Class User functionality. The class offers
 *  support for negotiating associations and sending and receiving arbitrary DIMSE messages
 *  on that connection. DcmSCU has built-in C-ECHO support so derived classes do not have to
 *  implement that capability on their own.
 */
class DCMTK_DCMNET_EXPORT DcmSCU
{

public:
    /** Constructor, just initializes internal class members
     */
    DcmSCU();

    /** Virtual destructor
     */
    virtual ~DcmSCU();

    /** Add presentation context to be used for association negotiation
     *  @param abstractSyntax [in] Abstract syntax name in UID format
     *  @param xferSyntaxes   [in] List of transfer syntaxes to be added for the given abstract
     *                             syntax
     *  @param role           [in] The role to be negotiated
     *  @return EC_Normal if adding was successful, otherwise error code
     */
    OFCondition addPresentationContext(const OFString& abstractSyntax,
                                       const OFList<OFString>& xferSyntaxes,
                                       const T_ASC_SC_ROLE role = ASC_SC_ROLE_DEFAULT);

    /** Initialize network, i.e.\ prepare for association negotiation. If the SCU is already
     *  connected, the call will not be successful and the old connection keeps open.
     *  @return EC_Normal if initialization was successful, otherwise error code.
     *          NET_EC_AlreadyConnected if SCU is already connected.
     */
    virtual OFCondition initNetwork();

    /** Negotiate association by using presentation contexts and parameters as defined by
     *  earlier function calls. If negotiation fails, there is no need to close the association
     *  or to do anything else with this class.
     *  @return EC_Normal if negotiation was successful, otherwise error code.
     *          NET_EC_AlreadyConnected if SCU is already connected.
     */
    virtual OFCondition negotiateAssociation();

    /** After negotiation association, this call returns the first usable presentation context
     *  given the desired abstract syntax and transfer syntax
     *  @param abstractSyntax [in] The abstract syntax (UID) to look for
     *  @param transferSyntax [in] The transfer syntax (UID) to look for. If empty, the transfer
     *                             syntax is not checked.
     *  @param requestorRole  [in] The role to look for (denoting the role the association
     *                             requestor plays)
     *  @return Adequate Presentation context ID that can be used. 0 if none found.
     */
    T_ASC_PresentationContextID findPresentationContextID(const OFString& abstractSyntax,
                                                          const OFString& transferSyntax,
                                                          const T_ASC_SC_ROLE requestorRole = ASC_SC_ROLE_DEFAULT);

    /** After a successful association negotiation, this function is called to return the
     *  presentation context ID that best matches the desired abstract syntax and transfer
     *  syntax (TS). The function tries to do the following:
     *  - If possible finds a presentation context with matching TS
     *  - Else then tries to find an explicit VR uncompressed TS presentation context
     *  - Else then tries to find an implicit VR uncompressed TS presentation context
     *  - Else finally accepts each matching presentation ctx independent of TS.
     *  @warning This method does not support filtering for a specific role, yet.
     *  @param abstractSyntax [in] The abstract syntax (UID) to look for
     *  @param transferSyntax [in] The transfer syntax (UID) to look for. If empty, the transfer
     *                             syntax is not checked.
     *  @return Adequate Presentation context ID that can be used. 0 if no appropriate
     *  presentation context could be found at all.
     */
    T_ASC_PresentationContextID findAnyPresentationContextID(const OFString& abstractSyntax,
                                                             const OFString& transferSyntax);

    /** This function sends a C-ECHO command via network to another DICOM application
     *  @param presID [in] Presentation context ID to use. A value of 0 lets SCP class tries
     *                     to choose one on its own.
     *  @return EC_Normal if echo was successful, an error code otherwise
     *
     */
    virtual OFCondition sendECHORequest(const T_ASC_PresentationContextID presID);

    /** This function sends a C-STORE request on the currently opened association and receives
     *  the corresponding response then. If required and supported, the dataset of the SOP
     *  instance can be converted automatically to the network transfer syntax that was
     *  negotiated (and is specified by the parameter 'presID'). However, this feature is
     *  disabled by default. See setDatasetConversionMode() on how to enable it.
     *  @param presID        [in]  Contains in the end the ID of the presentation context which
     *                             was specified in the DIMSE command. If 0 is given, the
     *                             function tries to find an appropriate presentation context
     *                             itself (based on SOP class and original transfer syntax of
     *                             the 'dicomFile' or 'dataset').
     *  @param dicomFile     [in]  The filename of the DICOM file to be sent. Alternatively, a
     *                             dataset can be given in the next parameter. If both are given
     *                             the dataset from the file name is used.
     *  @param dataset       [in]  The dataset to be sent. Alternatively, a filename can be
     *                             specified in the previous parameter. If both are given the
     *                             dataset from the filename is used.
     *  @param rspStatusCode [out] The response status code received. 0 means success, others
     *                             can be found in the DICOM standard.
     *  @param moveOriginatorAETitle [in] If this C-STORE is started due to a C-MOVE request,
     *                               this parameter informs the C-STORE SCP about the C-MOVE
     *                               client's AE title.
     *  @param moveOriginatorMsgID   [in] If this C-STORE is started due to a C-MOVE request,
     *                               this parameter informs the C-STORE SCP about the C-MOVE
     *                               message ID.
     *  @return EC_Normal if request could be issued and response was received successfully,
     *          error code otherwise. That means that if the receiver sends a response denoting
     *          failure of the storage request, EC_Normal will be returned.
     */
    virtual OFCondition sendSTORERequest(const T_ASC_PresentationContextID presID,
                                         const OFFilename& dicomFile,
                                         DcmDataset* dataset,
                                         Uint16& rspStatusCode,
                                         const OFString& moveOriginatorAETitle = "",
                                         const Uint16 moveOriginatorMsgID      = 0);

    /** Sends a C-MOVE Request on given presentation context and receives list of responses.
     *  The function receives the first response and then calls the function handleMOVEResponse()
     *  which gets the relevant presentation context together with the response dataset and
     *  status information. Then it waits again for the next response, if there are more to
     *  come (i.e. response status is PENDING). In the end, after receiving all responses, the
     *  full list of responses is returned to the caller. If he is not interested, he just sets
     *  responses=NULL when calling the function.
     *  This function can be overwritten by actual SCU implementations but should work just fine
     *  for most people.
     *  @param presID                 [in]  The presentation context ID that should be used.
     *                                      Must be an odd number.
     *  @param moveDestinationAETitle [in]  The move destination's AE title, i.e.\ the one that
     *                                      is used for connection to the storage server.
     *  @param dataset                [in]  The dataset containing the information about the
     *                                      object(s) to be retrieved.
     *  @param responses              [out] The incoming C-MOVE responses for this request.
     *                                      The caller is responsible for providing a non-NULL
     *                                      pointer for this case. After receiving the results,
     *                                      the caller is responsible for freeing the memory of
     *                                      this variable. If NULL is specified, the responses
     *                                      will not be returned to the caller.
     *  @return EC_Normal if everything went fine, i.e.\ if request could be send and responses
     *          (with whatever status) could be received.
     */
    virtual OFCondition sendMOVERequest(const T_ASC_PresentationContextID presID,
                                        const OFString& moveDestinationAETitle,
                                        DcmDataset* dataset,
                                        OFList<RetrieveResponse*>* responses);

    /** This is the standard handler for C-MOVE message responses: It just adds up all responses
     *  it receives and prints a DEBUG message. Therefore, it is called for each response
     *  received in sendMOVERequest(). The idea is of course to overwrite this function in a
     *  derived, actual SCU implementation if required. Thus, after each response, the caller of
     *  sendMOVERequest() can decide on its own whether he wants to cancel the C-MOVE session,
     *  terminate the association, do something useful or whatever. Thus this function is a more
     *  object-oriented kind of callback.
     *  @param presID              [in]  The presentation context ID where the response was
     *                                   received on.
     *  @param response            [in]  The C-MOVE response received.
     *  @param waitForNextResponse [out] Denotes whether SCU should try to receive another
     *                                   response. If set to OFTrue, then sendMOVERequest() will
     *                                   continue waiting for responses. The current
     *                                   implementation does that for all responses do not have
     *                                   status Failed, Warning, Success or unknown. If set to
     *                                   OFFalse, sendMOVERequest() will return control to the
     *                                   caller.
     *  @return EC_Normal, if response could be handled. Error code otherwise.
     *          The current implementation always returns EC_Normal.
     */
    virtual OFCondition handleMOVEResponse(const T_ASC_PresentationContextID presID,
                                           RetrieveResponse* response,
                                           OFBool& waitForNextResponse);

    /** Sends a C-GET Request on given presentation context and receives list of responses. It
     *  then switches control to the function handleCGETSession().
     *  The full list of responses is returned to the caller. If he is not interested, he can
     *  set responses=NULL when calling the function.
     *  This function can be overwritten by actual SCU implementations but just should work fine
     *  for most people.
     *  @param presID    [in]  The presentation context ID that should be used. Must be an odd
     *                         number.
     *  @param dataset   [in]  The dataset containing the information about the
     *                         object(s) to be retrieved
     *  @param responses [out] The incoming C-GET responses for this request. If the caller
     *                         specifies NULL, no responses will be returned; otherwise there
     *                         should be at least one final C-GET response (mandatory). C-GET
     *                         responses after each DICOM object received are optional and may
     *                         have been omitted by the server.
     *  @return EC_Normal if everything went fine, i.e.\ if request could be sent and expected
     *          responses (with whatever status) could be received.
     */
    virtual OFCondition sendCGETRequest(const T_ASC_PresentationContextID presID,
                                        DcmDataset* dataset,
                                        OFList<RetrieveResponse*>* responses);

    /** Does the logic for switching between C-GET Response and C-STORE Requests. Sends a C-GET
     *  Request on given presentation context and receives list of responses. The full list of
     *  responses is returned to the caller. If he is not interested, he can set responses=NULL
     *  when calling the function. After sending a C-GET Request, there might be two different
     *  responses coming in: C-GET-RSP (optional after each received object and mandatory after
     *  the last object) or a mandatory C-STORE for each incoming object that is received due to
     *  the request. This function therefore either calls handleCGETResponse() or
     *  handleSTORERequest() in order to deal with the incoming message. All other messages lead
     *  to an error within this handler.
     *  This function can be overwritten by actual SCU implementations but just should work fine
     *  for most people.
     *  @param presID    [in]  The presentation context ID that should be used. Must be an odd
     *                         number.
     *  @param dataset   [in]  The dataset containing the information about the object(s) to be
     *                         retrieved
     *  @param responses [out] The incoming C-GET responses for this request. If the caller
     *                         specifies NULL, no responses will be returned; otherwise there
     *                         should be at least one final C-GET response (mandatory). C-GET
     *                         responses after each DICOM object received are optional and may
     *                         have been omitted by the server.
     *  @return EC_Normal if everything went fine, i.e.\ if request could be send
     *          and expected responses (with whatever status) could be received.
     */
    virtual OFCondition handleCGETSession(const T_ASC_PresentationContextID presID,
                                          DcmDataset* dataset,
                                          OFList<RetrieveResponse*>* responses);

    /** Function handling a single C-GET Response. This standard handler reads the status of the
     *  response and decides whether to receive any further messages related to the original
     *  C-GET Request or whether the last response was received or an error occurred.
     *  @param presID              [in]  The presentation context the C-GET Response was
     *                                   received on.
     *  @param response            [in]  The response received
     *  @param continueCGETSession [out] Defines whether it is decided to wait for further C-GET
     *                                   Responses/C-STORE Requests within this C-GET session
     *  @return If no errors occur (dataset response NULL, SCU not connected), this method will
     *          return EC_Normal, otherwise error code.
     */
    virtual OFCondition handleCGETResponse(const T_ASC_PresentationContextID presID,
                                           RetrieveResponse* response,
                                           OFBool& continueCGETSession);

    /** Function handling a single C-STORE Request. If storage mode is set to disk (default),
     *  this function is called and the incoming object stored to disk.
     *  @param presID              [in]  The presentation context the C-STORE Request was
     *                                   received on.
     *  @param incomingObject      [in]  The dataset (the object) received. The function
     *                                   takes ownership of the dataset, i.e. deletes it
     *                                   after processing.
     *  @param continueCGETSession [out] Defines whether it is decided to wait for further
     *                                   C-GET Responses/C-STORE requests within this C-GET
     *                                   session.
     *  @param cStoreReturnStatus  [out] Denotes the desired C-STORE return status.
     *  @return If errors occur (incomingObject NULL or SCU not connected or file could not be
     *          stored), this method will return an error code otherwise EC_Normal.
     */
    virtual OFCondition handleSTORERequest(const T_ASC_PresentationContextID presID,
                                           DcmDataset* incomingObject,
                                           OFBool& continueCGETSession,
                                           Uint16& cStoreReturnStatus);

    /** Function handling a single C-STORE Request. If storage mode is set to bit preserving,
     *  this function is called and the incoming object stored directly to disk, i.e. not stored
     *  fully in memory.
     *  @param presID   [in] The presentation context the C-STORE Response was received on.
     *  @param filename [in] The filename to store to
     *  @param request  [in] The incoming C-STORE request command set
     *  @return If errors occur (incomingObject NULL or SCU not connected filename not
     *          specified), this method will return an error code otherwise EC_Normal.
     */
    virtual OFCondition
    handleSTORERequestFile(T_ASC_PresentationContextID* presID, const OFString& filename, T_DIMSE_C_StoreRQ* request);

    /** Sends a C-FIND Request on given presentation context and receives list of responses.
     *  The function receives the first response and then calls the function handleFINDResponse()
     *  which gets the relevant presentation context together with the response dataset and
     *  status information. Then it waits again for the next response, if there are more to
     *  come (i.e. response status is PENDING). In the end, after receiving all responses, the
     *  full list of responses is returned to the caller. If he is not interested, he just sets
     *  responses=NULL when calling the function.
     *  This function can be overwritten by actual SCU implementations but just should work fine
     *  for most people.
     *  @param presID    [in]  The presentation context ID that should be used. Must be an odd
     *                         number.
     *  @param queryKeys [in]  The dataset containing the query keys to be searched for on the
     *                         server (SCP).
     *  @param responses [out] The incoming C-FIND responses for this request. The caller is
     *                         responsible for providing a non-NULL pointer for this case.
     *                         After receiving the results, the caller is responsible for
     *                         freeing the memory of this variable. If NULL is specified, the
     *                         responses will be not returned to the caller.
     *  @return EC_Normal if everything went fine, i.e.\ if request could be send and responses
     *          (with whatever status) could be received.
     */
    virtual OFCondition
    sendFINDRequest(const T_ASC_PresentationContextID presID, DcmDataset* queryKeys, OFList<QRResponse*>* responses);

    /** This is the standard handler for C-FIND message responses: It just adds up all responses
     *  it receives and prints a DEBUG message. Therefore, it is called for each response
     *  received in sendFINDRequest(). The idea is of course to overwrite this function in a
     *  derived, actual SCU implementation if required. Thus, after each response, the caller of
     *  sendFINDRequest() can decide on its own whether he wants to cancel the C-FIND session,
     *  terminate the association, do something useful or whatever. That way this is a more
     *  object-oriented kind of callback.
     *  @param presID              [in]  The presentation context ID where the response was
     *                                   received on.
     *  @param response            [in]  The C-FIND response received.
     *  @param waitForNextResponse [out] Denotes whether SCU should try to receive another
     *                                   response. If set to OFTrue, then sendFINDRequest()
     *                                   will continue waiting for responses. The current
     *                                   implementation does that for all responses do not have
     *                                   status SUCCESS. If set to OFFalse, sendFINDRequest()
     *                                   will return control to the caller.
     *  @return EC_Normal, if response could be handled. Error code otherwise.
     *          The current implementation always returns EC_Normal.
     */
    virtual OFCondition
    handleFINDResponse(const T_ASC_PresentationContextID presID, QRResponse* response, OFBool& waitForNextResponse);

    /** Send C-CANCEL and, therefore, ends the C-FIND -GET or -MOVE session, i.e.\ no further
     *  responses will be handled. A call to this function only makes sense if an association
     *  is open, the given presentation context represents a valid C-FIND/GET/MOVE-enabled SOP
     *  class and usually only, if the last command send on that presentation context was a
     *  C-FIND message.
     *  @param presID [in] The presentation context ID where the C-CANCEL should be sent on.
     *  @param msgIDBeingRespondedTo [in] Optional message ID to respond with a C-CANCEL request.
     *                                    -1 means standard logic will take place. It should be
     *                                    provided when nextMessageId() is overridden.
     *                                    The value should fit UINT16_MAX.
     *  @return The current implementation always returns EC_Normal.
     */
    virtual OFCondition sendCANCELRequest(const T_ASC_PresentationContextID presID,
                                          const Sint32 msgIDBeingRespondedTo = -1);

    /** This function sends a N-ACTION request on the currently opened association and receives
     *  the corresponding response then
     *  @param presID         [in]  The ID of the presentation context to be used for sending
     *                              the request message. Should not be 0.
     *  @param sopInstanceUID [in]  The requested SOP Instance UID
     *  @param actionTypeID   [in]  The action type ID to be used
     *  @param reqDataset     [in]  The dataset to be sent
     *  @param rspStatusCode  [out] The response status code received. 0 means success,
     *                              others can be found in the DICOM standard.
     *  @return EC_Normal if request could be issued and response was received successfully,
     *          an error code otherwise
     */
    virtual OFCondition sendACTIONRequest(const T_ASC_PresentationContextID presID,
                                          const OFString& sopInstanceUID,
                                          const Uint16 actionTypeID,
                                          DcmDataset* reqDataset,
                                          Uint16& rspStatusCode);

    /** This function sends N-EVENT-REPORT request and receives the corresponding response
     *  @param presID         [in]  The ID of the presentation context to be used for sending
     *                              the request message. Should not be 0.
     *  @param sopInstanceUID [in]  The requested SOP Instance UID
     *  @param eventTypeID    [in]  The event type ID to be used
     *  @param reqDataset     [in]  The request dataset to be sent
     *  @param rspStatusCode  [out] The response status code received. 0 means success,
     *                              others can be found in the DICOM standard.
     *  @return EC_Normal if request could be issued and response was received successfully,
     *          an error code otherwise
     */
    virtual OFCondition sendEVENTREPORTRequest(const T_ASC_PresentationContextID presID,
                                               const OFString& sopInstanceUID,
                                               const Uint16 eventTypeID,
                                               DcmDataset* reqDataset,
                                               Uint16& rspStatusCode);

    /** Receives N-EVENT-REPORT request on the currently opened association and sends a
     *  corresponding response. Calls checkEVENTREPORTRequest() in order to determine the
     *  DIMSE status code to be used for the N-EVENT-REPORT response.
     *  @param reqDataset  [out] Pointer to the dataset received
     *  @param eventTypeID [out] Event Type ID from the command set received
     *  @param timeout     [in]  Optional timeout in seconds for receiving data. This value
     *                           (if not 0) overwrites the standard DIMSE timeout and also
     *                           enables the non-blocking mode for receiving the request.
     *  @return status, EC_Normal if successful, an error code otherwise
     */
    virtual OFCondition handleEVENTREPORTRequest(DcmDataset*& reqDataset, Uint16& eventTypeID, const int timeout = 0);

    /** This function sends N-CREATE request and receives the corresponding response.
     *  If successful, ownership of the created instance is handed over to the caller.
     *  @param presID                   [in]  The ID of the presentation context to be used for
     *                                        sending the request message. Should not be 0.
     *  @param affectedSopInstanceUID   [in]  The affected SOP Instance UID
     *  @param reqDataset               [in]  The request dataset to be sent
     *  @param createdInstance          [out] Pointer to the instance that was created. The caller
     *                                        is responsible for deleting the returned object.
     *  @param rspStatusCode            [out] The response status code received. 0 means success,
     *                                        others can be found in the DICOM standard.
     *  @return EC_Normal if request could be issued and response was received successfully,
     *          an error code otherwise. If a code different from EC_Normal is returned, other
     *          output like rspStatusCode may be invalid.
     */
    virtual OFCondition sendNCREATERequest(const T_ASC_PresentationContextID presID,
                                           const OFString& affectedSopInstanceUID,
                                           DcmDataset* reqDataset,
                                           DcmDataset*& createdInstance,
                                           Uint16& rspStatusCode);

    /** This function sends N-SET request and receives the corresponding response.
     *  @param presID                   [in]  The ID of the presentation context to be used for sending
     *                                        the request message. Should not be 0.
     *  @param requestedSopInstanceUID  [in]  The requested SOP Instance UID
     *  @param modificationList         [in]  Request dataset with attribute identifiers and values that
     *                                        should be replaced
     *  @param attributeList            [out] Pointer to response attribute list that was
     *                                        used to replace specified attributes. The caller is responsible
     *                                        for deleting the returned object.
     *  @param rspStatusCode            [out] The response status code received. 0 means success,
     *                                        others can be found in the DICOM standard.
     *  @return EC_Normal if request could be issued and response was received successfully,
     *          an error code otherwise. If a code different from EC_Normal is returned, other
     *          output like rspStatusCode may be invalid.
     */
    virtual OFCondition sendNSETRequest(const T_ASC_PresentationContextID presID,
                                        const OFString& requestedSopInstanceUID,
                                        DcmDataset* modificationList,
                                        DcmDataset*& attributeList,
                                        Uint16& rspStatusCode);

    /** Function handling a single C-GET, C-FIND or C-MOVE Response, used by
     *  handleCGETResponse(), handleFINDResponse() and handleMOVEResponse().
     *  It prints a message to the logger (warning, error or debug level related
     *  to the status code provided) and sets waitForNextResponse if the status
     *  provided is a DIMSE pending status.
     *  @param dimseStatus         [in]  The DIMSE status code to handle
     *  @param message             [in]  The message to be printed
     *  @param waitForNextResponse [out] Defines whether it is decided to wait for further
     *                                   Responses with the C-GET/FIND/MOVE session.
     *  @return If no processing errors occurs this method will return EC_Normal,
     *          otherwise an error code.
     */
    virtual OFCondition
    handleSessionResponseDefault(const Uint16 dimseStatus, const OFString& message, OFBool& waitForNextResponse);

    /** Closes the association created by this SCU. Also resets the current association.
     *  @note The direct call of this method by user code should be avoided.
     *    Please use releaseAssociation() or abortAssociation() instead.
     *  @param closeType [in] Define whether to release or abort the association
     */
    virtual void closeAssociation(const DcmCloseAssociationType closeType);

    /** Releases the current association by sending an A-RELEASE request to the SCP.
     *  Please note that this release only applies to associations that have been
     *  created by calling initNetwork() and negotiateAssociation().
     *  @return status, EC_Normal if successful, an error code otherwise
     */
    virtual OFCondition releaseAssociation();

    /** Aborts the current association by sending an A-ABORT request to the SCP.
     *  Please note that this abort only applies to associations that have been
     *  created by calling initNetwork() and negotiateAssociation().
     *  @return status, EC_Normal if successful, an error code otherwise
     */
    virtual OFCondition abortAssociation();

    /* Set methods */

    /** Set maximum PDU length (to be received by SCU)
     *  @param maxRecPDU [in] The maximum PDU size to use in bytes
     */
    void setMaxReceivePDULength(const Uint32 maxRecPDU);

    /** Set whether to send in DIMSE blocking or non-blocking mode
     *  @param blockingMode [in] Either blocking or non-blocking mode
     */
    void setDIMSEBlockingMode(const T_DIMSE_BlockingMode blockingMode);

    /** Set SCU's AE title to be used in association negotiation
     *  @param myAETtitle [in] The SCU's AE title to be used
     */
    void setAETitle(const OFString& myAETtitle);

    /** Set SCP's host (host name or IP address) to talk to in association negotiation
     *  @param peerHostName [in] The SCP's hostname or IP address to be used
     */
    void setPeerHostName(const OFString& peerHostName);

    /** Set SCP's AE title to talk to in association negotiation
     *  @param peerAETitle [in] The SCP's AE title to be used
     */
    void setPeerAETitle(const OFString& peerAETitle);

    /** Set SCP's port number to connect to for association negotiation
     *  @param peerPort [in] The SCP's port number
     */
    void setPeerPort(const Uint16 peerPort);

    /** Set timeout for receiving DIMSE messages
     *  @param dimseTimeout [in] DIMSE timeout in seconds for receiving data.
     *                           If the blocking mode is DIMSE_NONBLOCKING the SCU
     *                           will try to read data from the incoming socket stream
     *                           for the number of seconds configured.
     */
    void setDIMSETimeout(const Uint32 dimseTimeout);

    /** Set timeout for receiving ACSE messages
     *  @param acseTimeout [in] ACSE timeout in seconds used by timer for message timeouts
     *                          during association negotiation
     */
    void setACSETimeout(const Uint32 acseTimeout);

    /** Set timeout for connecting to the SCP. Setting the timeout to -1 sets an infinite
     *  timeout, i.e. any association request will wait forever (blocking) until the SCP
     *  accepts the connection request. A value of 0 lets the SCU return immediately if
     *  the SCP is not reachable at the first attempt. By default, the value of the global
     *  dcmConnectionTimeout is used.
     *  @param connectionTimeout [in] connection timeout in seconds when connecting
     *                                to SCPs. -1 will wait forever (blocking mode).
     */
    void setConnectionTimeout(const Sint32 connectionTimeout);

    /** Set an association configuration file and profile to be used
     *  @param filename [in] File name of the association configuration file
     *  @param profile  [in] Profile inside the association negotiation file
     */
    void setAssocConfigFileAndProfile(const OFString& filename, const OFString& profile);

    /** Set the directory that should be used by the standard C-GET handler to store objects
     *  that come in with the corresponding C-STORE requests
     *  @param storeDir [in] The directory to store to. It is checked in handleSTORERequest()
     *                       whether the directory is writeable and readable. By default, the
     *                       received objects are stored in the current working directory.
     */
    void setStorageDir(const OFString& storeDir);

    /** Set the storage mode to be used. Default is DCMSCU_STORAGE_DISK.
     *  @param storageMode The storage mode to be used.
     */
    void setStorageMode(const DcmStorageMode storageMode);

    /** Set whether to show presentation contexts in verbose or debug mode
     *  @param mode [in] Show presentation contexts in verbose mode if OFTrue. By default,
     *                   the presentation contexts are shown in debug mode.
     */
    void setVerbosePCMode(const OFBool mode);

    /** Set the mode that specifies whether the transfer syntax of the dataset can be changed
     *  for network transmission. This mainly covers the compression/decompression of datasets,
     *  which is disabled by default.
     *  @param mode [in] Allow dataset conversion if OFTrue
     */
    void setDatasetConversionMode(const OFBool mode);

    /** Set the mode that specifies whether the progress of sending and receiving DIMSE
     *  messages is notified by calling notifySENDProgress() and notifyRECEIVEProgress(),
     *  respectively. The progress notification is enabled by default.
     *  @param mode [in] Disable progress notification if OFFalse
     */
    void setProgressNotificationMode(const OFBool mode);

    /* Get methods */

    /** Get current connection status
     *  @return OFTrue if SCU is currently connected, OFFalse otherwise
     */
    OFBool isConnected() const;

    /** Returns maximum PDU length configured to be received by SCU
     *  @return Maximum PDU length in bytes
     */
    Uint32 getMaxReceivePDULength() const;

    /** Returns whether DIMSE messaging is configured to be blocking or unblocking
     *  @return The blocking mode configured
     */
    T_DIMSE_BlockingMode getDIMSEBlockingMode() const;

    /** Returns the SCU's own configured AE title
     *  @return The AE title configured for this SCU
     */
    const OFString& getAETitle() const;

    /** Returns the SCP's (peer's) host configured
     *  @return The host name (or IP) configured to be talked to
     */
    const OFString& getPeerHostName() const;

    /** Returns the SCP's (peer's) AE title configured
     *  @return The AE title configured to be talked to
     */
    const OFString& getPeerAETitle() const;

    /** Returns the SCP's (peer's) TCP/IP port configured
     *  @return The port configured to talked to
     */
    Uint16 getPeerPort() const;

    /** Returns DIMSE timeout in seconds for receiving data. If the blocking
     *  mode is DIMSE_NONBLOCKING the SCU will try to read data from
     *  the incoming socket stream for the number of seconds configured.
     *  @return The DIMSE timeout (in seconds) configured
     */
    Uint32 getDIMSETimeout() const;

    /** Returns ACSE timeout in seconds used by timer for message timeouts during
     *  association negotiation.
     *  @return The ACSE timeout (in seconds) configured
     */
    Uint32 getACSETimeout() const;

    /** Returns the timeout configured defining how long SCU will wait for the SCP when
     *  requesting an association. -1 means infinite waiting (blocking), 0 means no waiting
     *  at all.
     *  @return The connection timeout (in seconds)
     */
    Sint32 getConnectionTimeout() const;

    /** Returns the storage directory used for storing objects received with C-STORE requests
     *  in the context of C-GET sessions. Default is empty string which refers to the current
     *  working directory.
     *  @return The storage directory
     */
    OFString getStorageDir() const;

    /** Returns the storage mode enabled
     *  @return The storage mode enabled
     */
    DcmStorageMode getStorageMode() const;

    /** Returns the verbose presentation context mode configured specifying whether details
     *  on the presentation contexts (negotiated during association setup) should be shown in
     *  verbose or debug mode. The latter is the default.
     *  @return The current verbose presentation context mode. Show details on the
     *          presentation contexts on INFO log level (verbose) if OFTrue and on DEBUG
     *          level if OFFalse.
     */
    OFBool getVerbosePCMode() const;

    /** Returns the mode that specifies whether the transfer syntax of the dataset can be
     *  changed for network transmission. This mainly covers the compression/decompression
     *  of datasets, which is disabled by default.
     *  @return The current dataset conversion mode, enabled if OFTrue
     */
    OFBool getDatasetConversionMode() const;

    /** Returns the mode that specifies whether the progress of sending and receiving DIMSE
     *  messages is notified by calling notifySENDProgress() and notifyRECEIVEProgress(),
     *  respectively. The progress notification is enabled by default.
     *  @return The current progress notification mode, enabled if OFTrue
     */
    OFBool getProgressNotificationMode() const;

    /** Returns whether SCU is configured to create a TLS connection with the SCP
     *  @return OFFalse for this class but may be overridden by derived classes
     */
    OFBool getTLSEnabled() const;

    /** Deletes internal networking structures from memory */
    void freeNetwork();

protected:
    /** Sends a DIMSE command and possibly also a dataset from a data object via network to
     *  another DICOM application
     *  @param presID     [in]  Presentation context ID to be used for message
     *  @param msg        [in]  Structure that represents a certain DIMSE command which
     *                          shall be sent
     *  @param dataObject [in]  The instance data which shall be sent to the other DICOM
     *                          application; NULL, if there is none
     *  @param commandSet [out] If this parameter is not NULL it will return a copy of the
     *                          DIMSE command which is sent to the other DICOM application
     *  @return EC_Normal if sending request was successful, an error code otherwise
     */
    OFCondition sendDIMSEMessage(const T_ASC_PresentationContextID presID,
                                 T_DIMSE_Message* msg,
                                 DcmDataset* dataObject,
                                 DcmDataset** commandSet = NULL);

    /** Returns SOP Class UID, SOP Instance UID and original transfer syntax for a given dataset.
     *  If the dataset is NULL, all returned values will be undefined (i.e. empty or EXS_Unknown).
     *  @param dataset        [in]  The dataset to read from
     *  @param sopClassUID    [out] The value of attribute SOP Class UID if present
     *  @param sopInstanceUID [out] The value of attribute SOP Instance UID if present
     *  @param transferSyntax [out] The value of transfer syntax that originally was read from
     *                              disk. Will be unknown if the dataset was created in memory.
     *  @return EC_Normal if all information could be retrieved and is valid, an error code
     *    otherwise
     */
    OFCondition getDatasetInfo(DcmDataset* dataset,
                               OFString& sopClassUID,
                               OFString& sopInstanceUID,
                               E_TransferSyntax& transferSyntax);

    /** Tells DcmSCU to use a secure TLS connection described by the given TLS layer
     *  @param tlayer [in] The TLS transport layer including all TLS parameters
     *  @return EC_Normal if given transport layer is ok, an error code otherwise
     */
    OFCondition useSecureConnection(DcmTransportLayer* tlayer);

    /** Receive DIMSE command (excluding dataset!) over the currently open association
     *  @param presID       [out] Contains in the end the ID of the presentation context
     *                            which was specified in the DIMSE command received
     *  @param msg          [out] The message received
     *  @param statusDetail [out] If a non-NULL value is passed this variable will in the end
     *                            contain detailed information with regard to the status
     *                            information which is captured in the status element
     *                            (0000,0900). Note that the value for element (0000,0900) is
     *                            not contained in this return value but in internal msg. For
     *                            details on the structure of this object, see DICOM standard
     *                            part 7, annex C).
     *  @param commandSet   [out] If this parameter is not NULL, it will return a copy of the
     *                            DIMSE command which was received from the other DICOM
     *                            application. The caller is responsible to de-allocate the
     *                            returned object!
     *  @param timeout      [in]  If this parameter is not 0, it specifies the timeout (in
     *                            seconds) to be used for receiving the DIMSE command.
     *                            Otherwise, the default timeout value is used (see
     *                            setDIMSETimeout()).
     *  @return EC_Normal if command could be received successfully, an error code otherwise
     */
    OFCondition receiveDIMSECommand(T_ASC_PresentationContextID* presID,
                                    T_DIMSE_Message* msg,
                                    DcmDataset** statusDetail,
                                    DcmDataset** commandSet = NULL,
                                    const Uint32 timeout    = 0);

    /** Receives one dataset (of instance data) via network from another DICOM application
     *  @param presID     [out] Contains in the end the ID of the presentation context which
     *                          was used in the PDVs that were received on the network. If the
     *                          PDVs show different presentation context IDs, this function
     *                          will return an error.
     *  @param dataObject [out] Contains in the end the information which was received over
     *                          the network
     *  @return EC_Normal if dataset could be received successfully, an error code otherwise
     */
    OFCondition receiveDIMSEDataset(T_ASC_PresentationContextID* presID, DcmDataset** dataObject);

    /** clear list of presentation contexts. In addition, any currently selected association
     *  configuration file is disabled.
     */
    void clearPresentationContexts();

    /** After negotiation association, this call returns the presentation context belonging
     *  to the given presentation context ID
     *  @param presID         [in]  The presentation context ID to look for
     *  @param abstractSyntax [out] The abstract syntax (UID) for that ID.
     *                              Empty, if such a presentation context does not exist.
     *  @param transferSyntax [out] The transfer syntax (UID) for that ID.
     *                              Empty, if such a presentation context does not exist.
     */
    void findPresentationContext(const T_ASC_PresentationContextID presID,
                                 OFString& abstractSyntax,
                                 OFString& transferSyntax);

    /* ***********************************************************************
     *  Functions particularly interesting for overwriting in derived classes
     * *********************************************************************** */

    /** This function is called if an object was received due to a C-GET request and can be
     *  overwritten by a user in order to be informed about such an event. The default
     *  implementation just prints a DEBUG message. Note that this function is not called if
     *  the SCU is in storage mode DCMSCU_STORAGE_IGNORE.
     *  @param filename       [in] The filename written
     *  @param sopClassUID    [in] The SOP Class UID of the object written
     *  @param sopInstanceUID [in] The SOP Instance UID of the object written
     */
    virtual void
    notifyInstanceStored(const OFString& filename, const OFString& sopClassUID, const OFString& sopInstanceUID) const;

    /** This function is called while sending DIMSE messages, i.e.\ on each PDV of a dataset.
     *  The default implementation just prints a TRACE message on the number of bytes sent so
     *  far. By overwriting this method, the progress of the send process can be shown to the
     *  user in a more appropriate way. The progress notification can also be disabled
     *  completely by calling setProgressNotificationMode().
     *  @param byteCount [in] Number of bytes sent so far
     */
    virtual void notifySENDProgress(const unsigned long byteCount);

    /** This function is called while receiving DIMSE messages, i.e.\ on each PDV of a dataset.
     *  The default implementation just prints a TRACE message on the number of bytes received
     *  so far. By overwriting this method, the progress of the receive process can be shown to
     *  the user in a more appropriate way. The progress notification can also be disabled
     *  completely by calling setProgressNotificationMode().
     *  @param byteCount [in] Number of bytes received so far
     */
    virtual void notifyRECEIVEProgress(const unsigned long byteCount);

    /** Check given N-EVENT-REPORT request and dataset for validity. This method is called by
     *  handleEVENTREPORTRequest() before sending the response in order to determine the
     *  DIMSE status code to be used for the response message.
     *  @param request    [in] The N-EVENT-REPORT request message data structure
     *  @param reqDataset [in] The N-EVENT-REPORT request dataset received. Might be NULL.
     *  @return DIMSE status code to be used for the N-EVENT-REPORT response.
     *          Always returns STATUS_Success (0). Derived classes should, therefore,
     *          overwrite this method and return a more appropriate value based on the
     *          result of the checks performed.
     */
    virtual Uint16 checkEVENTREPORTRequest(T_DIMSE_N_EventReportRQ& request, DcmDataset* reqDataset);

    /** Sends back a C-STORE response on the given presentation context, with the designated
     *  status, fitting the corresponding C-STORE request.
     *  @param presID  [in] The presentation context ID to be used.
     *  @param status  [in] The storage DIMSE status to be used.
     *  @param request [in] The C-STORE request that should be responded to.
     *  @result EC_Normal if the response could be sent, error otherwise.
     */
    virtual OFCondition
    sendSTOREResponse(T_ASC_PresentationContextID presID, Uint16 status, const T_DIMSE_C_StoreRQ& request);

    /** Helper function that generates a storage filename by extracting SOP Class and SOP
     *  Instance UID from a dataset and combining that with the configured storage directory.
     *  The SOP class is used to create an initial two letter abbreviation for the
     *  corresponding modality, e.g. CT. An example for a storage filename created by this
     *  function is "/storage_dir/CT.1.2.3.4.5" for a CT with SOP Instance UID "1.2.3.4.5".
     *  This function might be overwritten to change the filename behaviour completely. This
     *  function is only called if the SCU is in DCMSCU_STORAGE_DISK mode.
     *  @param dataset [in] The dataset that should be stored to disk
     *  @result Non-empty string if successful, otherwise empty string.
     */
    virtual OFString createStorageFilename(DcmDataset* dataset);

    /** Receives a DICOM dataset on a given presentation context ID but does not store it in
     *  memory or disk, thus ignoring it.
     *  @param presID  [in] The presentation context to be used
     *  @param request [in] The corresponding C-STORE request
     *  @return EC_Normal if ignoring worked, error code otherwise.
     */
    virtual OFCondition ignoreSTORERequest(T_ASC_PresentationContextID presID, const T_DIMSE_C_StoreRQ& request);

    /** Returns next available message ID free to be used by SCU
     *  @return Next free message ID
     */
    virtual Uint16 nextMessageID();

    /* Callback functions (static) */

    /** Callback function used for sending DIMSE messages.
     *  @param callbackContext [in] The desired user callback data
     *  @param byteCount       [in] Progress bytes count
     */
    static void callbackSENDProgress(void* callbackContext, unsigned long byteCount);

    /** Callback function used for receiving DIMSE messages.
     *  @param callbackContext [in] The desired user callback data
     *  @param byteCount       [in] Progress bytes count
     */
    static void callbackRECEIVEProgress(void* callbackContext, unsigned long byteCount);

private:
    /** Private undefined copy-constructor. Shall never be called.
     *  @param src Source object
     */
    DcmSCU(const DcmSCU& src);

    /** Private undefined operator=. Shall never be called.
     *  @param src Source object
     *  @return Reference to this
     */
    DcmSCU& operator=(const DcmSCU& src);

    /// Association of this SCU. This class only handles 1 association at a time.
    T_ASC_Association* m_assoc;

    /// The DICOM network the association is based on
    T_ASC_Network* m_net;

    /// Association parameters
    T_ASC_Parameters* m_params;

    /// Configuration file for presentation contexts (optional)
    OFString m_assocConfigFilename;

    /// Profile in configuration file that should be used (optional)
    OFString m_assocConfigProfile;

    /// Defines presentation context, consisting of one abstract syntax name
    /// and a list of transfer syntaxes for this abstract syntax
    struct DCMTK_DCMNET_EXPORT DcmSCUPresContext
    {
        /** Default constructor
         */
        DcmSCUPresContext()
            : abstractSyntaxName()
            , transferSyntaxes()
            , roleSelect(ASC_SC_ROLE_DEFAULT)
        {
        }
        /// Abstract Syntax Name of Presentation Context
        OFString abstractSyntaxName;
        /// List of Transfer Syntaxes for Presentation Context
        OFList<OFString> transferSyntaxes;
        /// Role Selection
        T_ASC_SC_ROLE roleSelect;
    };

    /// List of presentation contexts that should be negotiated
    OFList<DcmSCUPresContext> m_presContexts;

    /// Configuration file containing association parameters
    OFString m_assocConfigFile;

    /// The last DIMSE successfully sent, unresponded DIMSE request
    T_DIMSE_Message* m_openDIMSERequest;

    /// Maximum PDU size (default: 16384 bytes)
    Uint32 m_maxReceivePDULength;

    /// DIMSE blocking mode (default: blocking)
    T_DIMSE_BlockingMode m_blockMode;

    /// AE title of this application (default: ANY-SCU)
    OFString m_ourAETitle;

    /// Peer host (IP or host name)
    OFString m_peer;

    /// AE title of remote application (default: ANY-SCP)
    OFString m_peerAETitle;

    /// Port of remote application entity (default: 104)
    Uint16 m_peerPort;

    /// DIMSE timeout (default: unlimited)
    Uint32 m_dimseTimeout;

    /// ACSE timeout (default: 30 seconds)
    Uint32 m_acseTimeout;

    /// TCP connection timeout (default: value of global dcmConnectionTimeout)
    Sint32 m_tcpConnectTimeout;

    /// Storage directory for objects received with C-STORE due to a running
    /// C-GET session. By default, the received objects are stored in the current
    /// working directory.
    OFString m_storageDir;

    /// Set whether bit preserving storage should be enabled, i.e.\ any objects
    /// retrieved via C-STORE should be written directly to disk without any data
    /// correction/re-computation (e.g.\ group length calculations, padding, etc.).
    /// This is especially interesting for retaining valid signatures, and also to
    /// receive huge files which cannot be fully received in memory.
    /// Default value: DCMSCU_STORAGE_DISK
    DcmStorageMode m_storageMode;

    /// Verbose PC mode (default: disabled)
    OFBool m_verbosePCMode;

    /// Dataset conversion mode (default: disabled)
    OFBool m_datasetConversionMode;

    /// Progress notification mode (default: enabled)
    OFBool m_progressNotificationMode;
};

#endif // SCU_H
